The present invention relates to a device for determining the presence and/or quantity of one or more analytes in a sample of human body fluid, comprising a container for receiving a sample of body fluid, and further comprising at least one test strip with an absorbent section and with reagents for determining the presence and/or quantity of one or more analytes in the sample.
More specifically, the present invention concerns a device for collecting and testing a liquid sample, as is used in particular in tests for a drug or for multiple drugs. For this purpose, the presence and/or quantity of one or more analytes, in particular drugs of abuse, is determined from a sample of a body fluid, for example saliva or urine. The result can be determined visually by means of test strips.
Various analytical devices with which analytes in a sample can be detected are known from, for example, EP 0 225 054, EP 0 183 442, EP 0 186 799, EP 0 299 359 and WO 89/06799. All of these devices use test strips impregnated with reagents in specific binding assays in which a liquid sample is applied to an end of the test strip and migrates across or through the test strip. The test strip can in these cases be provided in a cover. If the analyte that is to be detected is present in a sample, it can be detected by a binding reagent immobilized in a detection zone, for example by a sandwich assay or a competitive assay.
Moreover, test cards are known that comprise test strips with which amphetamines and drugs such as ecstasy, cocaine, crack or opiates and cannabis are intended to be detected in parallel.
Suitable detection methods are, for example, immunoassays, which are highly sensitive detection methods based on the specificity of immunological reactions. The substances are detected using an easily detectable and measurable indicator substance, for example radioactive isotopes, enzymes, dyes, for example gold sols, and fluorescence dyes.
The tests presently on the market are solid-phase tests. A marked antigen or a marked antibody, which is specific for the substance to be detected, is located in a first zone which first comes into contact with the liquid sample. If the sample contains an analyte that is recognized by the specific antibodies or antigens, these bind to the analyte and migrate with the latter through the solid carrier as far as a second zone, where a further reagent is bound which also specifically recognizes either the analyte or the antibody/antigen. The binding of the analyte-antibody/analyte-antigen reaction product in the second zone means that the analyte can be detected, for example, by an accumulation of the markers, or by a chemical reaction triggered by the binding.
Solid-phase immunoassays in the competitive or sandwich technique are known to persons skilled in the art and for this reason do not have to be explained in detail here.
Moreover, DE 200 21 659 U1 discloses a device in which samples of body fluid, in particular urine, are tested for a plurality of drugs of abuse simultaneously. Test strips are arranged on a test card, each strip being sensitive to a specific drug of abuse and having a visible limit value in order to indicate the presence or absence of a specific drug. The container used has, at its upper end, a closure lid which has a slot of such a size that a test card with test strips can be fitted therein. The test card can be inserted through the slot in such a way that one end is immersed in the urine sample to a predetermined depth, the visible result from each test strip being able to be seen by virtue of the transparency of the wall of the container without removing the test card from the container. When samples test “positive”, it is necessary for the slotted lid to be replaced by a second, unslotted lid and to remove the test card from the container, in order then to be able to send the closed container to a certified laboratory.
Another disadvantage of the tests known from the prior art is that, for an initial detection of the drugs, sufficient quantities, i.e., relatively large quantities, of body fluids are needed in order to allow the tests to be carried out. Particularly for detecting drugs in saliva, the consistency and availability of the latter mean that quite large quantities are needed, which makes rapid drug detection, for example of the kind that is intended to be performed in direct on-site tests, difficult to achieve when using saliva. For this reason, most of the presently available tests are based on the use of urine samples.